JPH0296181A - Electrophotographic yellow toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic yellow toner having improved chargeability, spectral reflection characteristics, and color miscibility by incorporating a specified compd. as charge controlling agent and an acetoacetarylide type monoazo- or disazo pigment as coloring pigment into a polyester or epoxy resin. CONSTITUTION:A compd. classified into C.I. Solvent Yellow 25 as charge controlling agent and an acetoacetarylide type monoazo or disazo pigment as coloring pigment are incorporated into a polyester or epoxy resin. A distribution of the charge controlling component in the individual fine particles of the toner prepd. by melting the mixture, kneading the mixture, and granulating the kneaded product is made uniform. Thus, an electrophotographic yellow toner having uniform chargeability, superior spectral reflection characteristics, and superior color miscibility, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a color toner for electrophotography, and particularly to a yellow toner for electrophotography that provides a clear colored image.

(Prior Art) Conventionally, in a copying machine using an electrophotographic method, an electrostatic latent image formed on a photoreceptor having a photosensitive layer containing an inorganic or organic photoconductive substance is visualized by a dry developing method. Various powder toners containing colorants, binder resins, etc. are used.

In the electrophotographic method, an electrostatic latent image formed on the photoreceptor by charging and exposure to light is developed with the toner, and a toner image formed corresponding to the electrostatic latent image is transferred to a support such as transfer paper. At the same time as the transfer, the toner image is fixed on the support by a fixing means such as a heating roller or a pressure roller, thereby making the electrostatic latent image visible. Further, after the toner image is transferred to the support, the residual toner on the photoreceptor is removed by a cleaning blade in order to clean the toner remaining on the photoreceptor.

Currently, a black toner whose main components are a black pigment and a fixing binder resin is generally used as the toner.
Furthermore, various color toners are manufactured by using chromatic pigments as pigments. The color toner, like the black toner, must have excellent charging properties, and a method that utilizes frictional charging of a resin, which is a component of the toner, has been known as a method for imparting an electric charge to the toner during the development. ing. However, in such a method, since the amount of charge of the toner is small, C, I, Solvent Red 177 (Japanese Patent Application Laid-Open No. 58118654), 1-(2-hydroxy 3.5-dinitrophenylazo)-3-phenyl It has been proposed that a charge control agent composed of dyes and pigments such as carbamoyl-2-naphthol 1:2 type chromium complex salts, naphthenic acid metal salts, and fatty acid metal soaps is added to toner as an additive that imparts chargeability. ing.

On the other hand, as properties specific to the color toner, it is necessary to have excellent spectral reflection characteristics and color mixing properties, and conventionally C.
．． I. Pigment-Red48 and C01, Pi
Toner containing gment-Red81 (Japanese Unexamined Patent Application Publication No. 62
As shown in Japanese Patent Publication No. 49359), various types of materials using limited materials such as coloring agents have been proposed.

(Problems to be Solved by the Invention) However, many of the dyes and pigments conventionally used as charge control agents have low compatibility with resins, and all require dispersion in a binder resin. There were problems with the dispersion method, stability of the dispersion, etc.

That is, it is difficult to uniformly disperse insoluble pigments and dyes with low compatibility in the binder resin, which complicates the dispersion process. Moreover, due to the low compatibility with the resin, the components in the individual toner particles produced become non-uniform, and the charge imparted to the toner varies. Large or small particles may be formed, and in some cases, fine particles consisting only of dyes or pigments may also be present.

As a result, the image obtained by development may become foggy and unclear, or even if it shows good developability at the beginning of use, the developing ability may deteriorate with continued use, or the copying may become difficult due to increased toner scattering. There were problems such as contamination inside the aircraft.

Furthermore, since pigments are aggregates, differences in the conditions of the pigment manufacturing process greatly affect the characteristics of the manufactured toner, and it is extremely difficult to control the physical properties of pigments to solve this problem.

In addition, in color toners, the color of the charge control agent itself greatly affects the color mixing properties, spectral reflection characteristics, etc. of the toner even when the amount contained in the toner is small. Therefore, there is a continuing need for a suitable combination of color pigments and charge control agents, which are constituent components of color toners, with respect to the hue of the toner.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of conventional electrophotographic toners, and to provide electrophotographic toners that are uniformly charged, have excellent charging ability, and have good spectral reflection characteristics and color mixing properties. Our goal is to provide yellow toner.

(Means and effects for solving the problems) The present invention has the following features:
Electrophotographic yellow containing a compound classified as C1I or Solvent Yellow 25 as a charge control agent and an acetoacetate allylide monoazo pigment or an acetoacetate allylide disazo pigment as a coloring pigment in a polyester resin or epoxy resin. The above objectives were achieved by constructing a toner.

As a result of intensive research, the present inventors have discovered that oil-soluble dyes classified as C11 and Solvent Yellow 25 are extremely well soluble in polyester resins or epoxy resins, and that acetoacetate arylide monoazo pigments It has also been found that a compound classified as an acetoacetate allylide-based disazo pigment provides a clear yellow color with extremely good spectral reflection characteristics.

Furthermore, as a result of intensive research, we found that the C1I, Solvent Yellow 25, which dissolves extremely well in polyester resins or epoxy resins, and an acetoacetate allylide monoazo pigment or acetoacetate allylide disazo pigment, are used as constituent components of electrophotographic toners. It has been discovered that a vivid yellow toner with particularly excellent color mixing properties can be obtained by combining compounds classified into the following.

Therefore, since the yellow toner for electrophotography of the present invention uses the above-mentioned components, the charge control agent component in each TOCHI fine particle produced by melt-kneading and granulating the same becomes uniform. As a result, it is possible to obtain a yellow toner for electrophotography which has extremely uniform charging properties without uneven charging, and also has good spectral reflectivity and color mixing properties.

Also, C0! The charge amount of Solvent Yellow 25, for example, when measured by blow-off after mixing with a ferrite carrier, is on the order of about -34.0 μc/g,
Above C. I. It can be seen that Solvent Yellow 25 functions satisfactorily as a charge control agent.

(Preferred Embodiment of the Invention) Any polyester resin can be used as the binder resin in the present invention, but from the viewpoint of non-offset property and fixing property, the following - Saito, H3 (in the formula, R is is an ethylene group or a propylene group, m
and n is a positive integer) and a polyhydric carboxylic acid, its acid anhydride, or its derivative as an acid component. .

The diol component represented by the above-mentioned shipman includes polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane.
Examples include hydroxyphenyl)propane, polyoxypropylene-polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane, and the like.

Carboxylic acid components include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, fucuric acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, acyhinic acid, sepacic acid, malonic acid, Riluic acid, 1,2.4 henzenetricarboxylic acid, 1.2.5 benzenetricarboxylic acid, 1,
2.4 cyclohexanetricarboxylic acid, 2,5.7 naphthalenetricarboxylic acid, 1.2.4 naphthalenetricarboxylic acid, 1,2.5 hexanetricarboxylic acid, 1.2.
4-butanetricarboxylic acid, 1,3-dicarboxy-2-methylcarboxypropane, 1,3-dicarboxy-2-
Mention may be made of methyl-2-methylcarboxypropanetetra(methylenecarboxy)methane, 1,2,7.8 octanetetracarboxylic acid, embol trimer, and acid anhydrides thereof.

This polyester resin is produced by condensation polymerization of the diol component and polyhydric carboxylic acid component,
At this time, the number of carboxyl groups in the carboxylic acid component is 1.2 to 0.0 relative to the number of hydroxyl groups in the diol component.
8, particularly preferably from 1.1 to 0.9, and as the catalyst, tin oxide, zinc oxide, titanium oxide, dibutyltin oxide, dibutyltin diurarate, etc. are used. Furthermore, in addition to the etherified bisphenol shown in the above-mentioned ``Shipin'', other diol components such as ethylene glycol and bisphenol A can be used in combination within a range of 10 mol%.

Furthermore, any epoxy resin can be used as the binder resin in the present invention, but includes those having an average of two or more epoxy groups in one molecule; Generally, the softening temperature is 50~
170”C1 especially within the range of 60-150°C,
The molecular weight is within the range of 700 to 8000, especially 900 to 6000, and the epoxy equivalent is 150 to 4000, especially 200.
Advantageously, it is in the range ˜3500.

Examples of such epoxy resins include bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, novolak epoxy resins, polyalkylene ether epoxy resins, and cycloaliphatic epoxy resins.

As the acetoacetate arylide monoazo pigment which is a constituent component of the present invention, any one can be used, but for example, the following -
As the disazo pigment, any one can be used, but for example, the following - Shipin (in the formula, R1 is an alkyl group, an alkoxy group, a nitro group,
R2 is a halogen atom, an alkyl group, an alkoxy group, a nitro group, an aromatic-substituted sulfamoyl group, and C
a, a sulfo group or carboxyl group substituted with a heavy metal such as Ba, Mn, Sr, R3, R1, R5, and R6 are hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups,
Acetoacetate allylide monoazo pigment represented by C.I. I. Pigment-Yellow
, C0I, Pigment-Yellow3, C61,
Pigment-Yellow65, C, I.

Pigment-Ye I low74, C. I. Pi
gment-Yellow97, C, T, Pigm
ent-Ye 11ow98, C0I, Pigment
-Ye I low133, C. I. Pigment-
Examples include Yellow 69.

Acetoacetate arylide, which is a component of the present invention (in the formula,
R7 is a hydrogen atom, an alkyl group, an alkoxy group, R is a hydrogen atom, a halogen atom, an alkyl group, R7 is a hydrogen atom,
an alkoxy group), specifically an acetoacetate arylide-based disazo pigment represented by C.I. I. Pigment-Y
yellowl2, C. I. Pigment-Yello
wl3, C. I. Pigment-Yellow4,
C01, Pigment-Yellow7, C1I.

Pigment-Yellow55, C.I. I. Pigm
ent-Yellow83 and the like.

The above-mentioned color pigment is used in an amount of 1 to 15 parts by weight per 100 parts by weight of the binder resin for toner. If the amount is less than the above range, the color tone of the yellow toner will not be maintained, and if the amount is more than the above range, the chargeability will be seriously affected, which is not preferable.

In the present invention, C is used as a charge control agent together with a color pigment.
．． I. It is preferable to use Solvent Yellow 25 in an amount of 0.5 to 10% by weight, especially 1 to 5% by weight, based on the binder resin for toner. If it is less than the above range, there is no charge control effect; If the amount exceeds 1, the stability of the toner deteriorates and problems such as carrier contamination occur.

In the electrophotographic toner of the present invention, toner compounding agents known per se can be blended according to known formulations.

The toner is manufactured by blending a predetermined amount of the above-mentioned composition, melting and kneading it in a roll mill, and granulating the mixture. For molding, the above-mentioned mixed wire composition is cooled, then coarsely ground with a hammer mill, and further finely ground with a jet mill. Of course, rapid mechanical stirring may be used to round off irregularly shaped particles. The particle size of the toner particles may be related to resolution, etc., but is generally preferably within the range of 5 to 35 microns.

(Effects of the Invention) The toner of the present invention uses a polyester resin or an epoxy resin as a toner binder resin, and contains C1■ and Solvent Yellow 25, which are extremely compatible with the resin. Charge is uniformly applied, and it has stable chargeability even after repeated development through continuous use.Furthermore, by combining an acetoacetate arylide monoazo pigment or an acetoacetate arylide disazo pigment as a coloring pigment, it has good spectral reflection properties. It has color mixing properties and can maintain clear images.

(Example) Hereinafter, the present invention will be explained in Examples.

As a binder, 100 parts by weight of polyester resin, as a coloring agent, C.I. I. Pigment-Ye11ow97(
(acetoacetate arylide monoazo pigment) 8.5 parts by weight As a charge control agent, C, I, Solvent Yellow 2
5 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5PILON YE
LLOW 3RH) 2 parts by weight The mixture of the above toner materials is melt-kneaded, cooled, pulverized, and further classified to produce the toner of the present invention, and further mixed with 5 parts by weight of the above toner and a carrier (manufactured by Nippon Tetsuko Co., Ltd., trade name 5FC150)9
A developer sample was prepared by mixing 5 parts by weight.

Example I A developer sample was produced in the same manner as in Example 1, except that an epoxy resin was used as the binder resin in place of the polyester resin used in Example 1.

Sharp opening J C used as a coloring agent in Example 1, 1. Pig
ment-Yellow97 (acetoacetate allylide-based monoazo pigment), C.I. I. Pigment-Y
A developer sample was produced in the same manner as in Example 1, except that yellow17 (acetoacetate arylide-based disazo pigment) was used.

Example 111: C, which was used as a coloring agent in Example 2, 1. Pig
C0I, Pigment
A developer sample was produced in the same manner as in Example 2, except that -Yellow17 (acetoacetate arylide-based disazo pigment) was used.

Comparison 1. C, which was used as a soil charge control agent in Example 1, 1. Solvent Yellow 25 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5PIL)
ON YELLOW 3RH) instead of C. I. A developer sample was produced in the same manner as in Example 1, except that Solvent Yellow 61 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON YELLOW 3RH3P) was used.

Comparative Example I C used as a charge control agent in Example 2, 1. Solvent Yellow 25 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5P
C91 instead of ILON YELLOW 3RH)
, Solvent Yellow 61 (manufactured by Hodogaya Chemical Industry Co., Ltd.)
Product name 5PILON YELLOW 3RH3P)
A developer sample was produced in the same manner as in Example 2, except that the developer sample was used.

This l■ discharge 1 C, which was used as a coloring agent in Example 1, 1. Pigment
-Yellow97 (acetoacetate allylide monoazo pigment), C.I. I. Pigment-Yello
A developer sample was produced in the same manner as in Example 1 except that w138 (quinophthalone pigment) was used.

, C, which was used as a comparative coloring agent in Example 2, 1. Pigment
-Yellow97 (acetoacetate allylide monoazo pigment), C.I. I. Pigment-Yello
A developer sample was produced in the same manner as in Example 2 except that w13B (quinophthalone pigment) was used.

Each developer obtained in the above example was applied to a copying machine D manufactured by Sandako Co., Ltd. (
, -A2 and made 20,000 continuous copies. As a result, when the developers of Examples 1 to 4 were used, yellow images with very good spectral reflection characteristics without fog were obtained, with almost no image deterioration through 20,000 sheets, and with almost no toner scattering. I couldn't see it. On the other hand, when the developers of Comparative Examples 1 and 2 were used, significant fogging occurred and clear images could not be obtained. Further, when the developers of Comparative Examples 3 and 4 were used, the color tone was dull and the copy quality was dull.

Table 1 shows the types of dyes and binder resins used in the experiment and the results of measuring their solubility.

O: dissolves in resin ×: Does not dissolve in resin

Claims (1)

[Claims] C.I. as a charge control agent in polyester resin or epoxy resin. I. A yellow toner for electrophotography characterized by containing a compound classified as Solvent Yellow 25 and an acetoacetate allylide monoazo pigment or an acetoacetate allylide disazo pigment as a coloring pigment.